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  #16  
Old 01-21-2007, 01:40 PM
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Today I tested the circuit again. This time with digital meter. The reading between the spring contact point and a ground was .2 Ohms. I unplugged the antenna power plug in the trunk and tested the circuit again. Same result. I then checked the same points with an analog meter. The reading was the same as with the probes touched together. The weather is rainy and cold so I retreated to the house. I wondered why the reading with the digital meter wasn't zero. I touched the probes together and got same .2 Ohms as on the circuit. The meter doesn't get used too often so I moved the batteries around for a better contact. That brought the reading to zero. It was raining when I unplugged the antenna plug. I didn't look for a second plug. My thought is there is short to ground somewhere in the circuit but not at the front dome light or the antenna power. Any more suggestions? Thanks for your help Robert.

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  #17  
Old 01-21-2007, 02:54 PM
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Originally Posted by Wired_Bob View Post
. My thought is there is short to ground somewhere in the circuit but not at the front dome light or the antenna power. Any more suggestions? Thanks for your help Robert.
I agree.

Disconnect the vaccum pump in the base of the trunk.
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  #18  
Old 01-21-2007, 04:42 PM
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Done. Still no change.
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  #19  
Old 01-21-2007, 05:00 PM
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Done. Still no change.
Find the wires in the trunk that lead to the trunk lamp. They typically go along the left side arm. They are constantly working at this point and they can break at this location. You can't see the break due to the wire covering. But, feel along the wires for a broken or twisted connection. Just your act of moving the wires might make a difference in the short. See if any movement along the wires can temporarily cure the short.
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  #20  
Old 01-22-2007, 10:46 PM
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Disconnected trunk light. Found trunk light wires. Pulled wires from channels it was routed through. Looked and touched as much wire as I could pull out. Found one wire that had been scuffed. Thought I had hit pay-dirt. Made sure it wasn't touching the body. Checked with analog meter. Slightly more resistance than shorting probes together. Just to be sure I installed a new fuse and watched it melt. I have been trying to figure out the CD manual since last nights experiment. Some of it is beginning sense. From the fuse list there is seven systems powered by that fuse. I think I have eliminated anti-theft, courtesy lights and automatic antenna. Without any quick check shortcuts, I will be checking each system one at time one part at a time. This car has as many circuits as a space shuttle. Anybody have suggestions that will shorten this saga? Thanks Robert
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  #21  
Old 01-22-2007, 11:31 PM
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One way you can speed things up a bit is to connect a 12 volt lamp between the two points of the fuseholder. The lamp will glow at full brightness as long as the short to ground exists. There will be no danger of overheating the circuit, as the lamp filament acts as the load. Plus you will not need to sacrifice any more fuses. As soon as you disconnect the shorted section of the circuit, the lamp will go out or will dim significantly. This is an electricians trick we use when looking for a short circuit in house wiring, except we use a 120 volt lamp.
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  #22  
Old 01-22-2007, 11:43 PM
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Also, on your resistance checks, divide the reading into the battery voltage to get the amp draw. With only .2 ohms of resistance and 12 volts you will draw 60 amps, which will fry your little fuse. The higher the resistance, the lower the amp draw. How many amps is fuse #15 rated for?
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87 300Dturbo 180K #14 head still running R-12 SOLD 12/2017
02 F350 Powerstroke 180K
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08 Infiniti FX-35 40K
15 Golf Sportwagen TDI 35K
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  #23  
Old 01-22-2007, 11:44 PM
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This car has as many circuits as a space shuttle. Anybody have suggestions that will shorten this saga? Thanks Robert
I hear 'ya.

Unfortunately, it gets tougher from here.

If you've ruled out the anti-theft system, the only things left are the two front door actuators and the trunk lock actuator. One of these items must be the culprit. There's a loose wire in or near the actuators or the wires into or out of the doors have broken. The actuator wires are all red with white stripe, so, if you can find them and disconnect or cut them before they head into the door..........you won't need to dismantle the door just to rule it out. There's a junction of all these supply lines at X48A, but, I've got no clue where that might be.
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  #24  
Old 01-24-2007, 07:24 PM
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Weather has been cold and I have been working till after dark. Since this problem isn't mission critical I haven't gone any farther. The answer to amp question is .8 Ohms. I got this by figuring that 15 Amps is 1/4 of the 60 Amps @ .2 Ohms. But to check this I looked up an Ohms law equations to confirm my logic. I have been studying the wiring diagram and mapping a plan. The doors and the central locking system is where I will be checking next. The first stop will be X48a terminal. I believe it's on right side of the driver footwell Stay tuned this could be a while in the resolving. One other thing. The meter i use has tone mode for checking continuity. The idea of using a 12 volt lamp is a better choice. Thanks again for the help. Robert


Last edited by Wired_Bob; 01-24-2007 at 07:28 PM. Reason: error
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